Osteoarthritis or degenerative joint disease is a disease involving cartilage and bone destruction that is characterized by pain, stiffness, and limited mobility. It is a more common disorder in adults. Old age and heredity are two factors strongly associated with the development of osteoarthritis. Osteoarthritis affects most people to some degree by age 70.
Although osteoarthritis affects a larger percentage of older population, it is not true that it is an inevitable part of aging, like gray hair and skin wrinkles. It is not caused simply by the wear and tear that results with years of use. Experts believe that the more responsible factors causing osteoarthritis are microscopic changes in the structure and composition of cartilage
A poor immune system, some endocrine problems or some injury or infection are among some common causes of osteoarthritis. But one of the most important causes is also the extra ugly fat on your body.
The natural structure of a joint is so perfect that there is little scope for wear and tear even after prolonged use. Osteoarthritis is nevertheless a reality. Let us see how it develops. In the beginning, the cells which make the components of cartilage (collagen and proteoglycans) go abnormal. The cartilage then undergoes inflammation (swelling) due to water retention, becomes soft, and results in developing cracks on the surface.
Very small cavities are then formed in the bone below the cartilage thereby weakening the bone. Most components of the joint such as the synovial fluid, ligaments, tendons etc. fail to a more or less degree. Prominent bumps are sometimes formed due to bone overgrowth at the edges of the joint. Finally, the smooth, lubricated surface of the cartilage becomes rough and pitted resulting in abnormal movement. Here the mobility, range of motion and smoothness of movement may be lost. Such joint can hardly absorb any impact.
The symptoms develop gradually. The joint pain is usually aggravated by putting load on the joint. For example, in case of knee joint, at rest the pain may be insignificant to cause any panic. But it may become unbearable while climbing stairs. Or in case of low back pain, it may aggravate while lifting even a small weight.
In some cases, the joint becomes very stiff after sleep, but the stiffness usually subsides after say 20 to 30 minutes of working the joint.
When the condition becomes worse, the symptoms aggravate, the stiffness increases and the range of motion diminishes causing loss of function and increased pain. The body responds by attempting to repair the damage to the tissue. But in doing so osteoarthritis becomes worse. How? While repairing the damage the body irregularly grows more cartilage, bone or other tissue which in turn results in the enlargement of the joint. Thus body’s response makes more harm than good and now the joint starts to crackle and grate due to the new irregular growth. The so called Heberden’s nodes are the bony growths at the ends or the middle of fingers.
The joint becomes unstable when the supporting ligaments stretch due to uneven load usually caused in a sports injury or in an accident.
Although back pain is very common particularly in people with sedentary lifestyle, the cause is not always sedentary lifestyle. Some times a fall may result into slipped disk (or herniated disk) whish in turn may cause back pain. If the herniated disk encroaches onto nerves, then pain, numbness, tingling sensation or weakness in one arm or leg may result. There may be an overgrowth of a bone in the spine. This overgrowth of bone may be pressing the nerves (going to legs) within the spinal canal. Pain may result after walking. Many people may infer from this that there is inadequate blood supply to legs (this condition is known as intermittent claudication:peripheral arterial disease) which is wrong.
Knee pain is another major problem. Because of the structure and the load placed on the knee joint, it is the largest and most vulnerable joint for injury and pain. Knee joint is at the junction of the femur and the tibia. For the smooth articulation of the knee joint there is a special and unique arrangement of the Patella (or the kneecap). It slides in a groove on the lower end of the femur. For the stability of the knee joint, it is supported by several ligaments. To absorb the shock to the joint, a lining of special cartilage tissue called as meniscus is provided as a cushion on the ends of both femur and tibia.